Nozzle insert for an arc welding apparatus

ABSTRACT

A consumable assembly for use in an arc welding apparatus is provided that includes a nozzle assembly having a nozzle body, an insulator disposed within the nozzle body, and a nozzle insert disposed within the insulator. The nozzle insert includes an internal gas diverter. A contact tip is disposed within the nozzle assembly and includes at least one aperture extending from an exterior portion to an internal cavity, an exit orifice, a distal end face, and an exterior surface extending between the at least one aperture and the distal end portion of the contact tip. The internal gas diverter directs a flow of shield gas exiting the at least one aperture along the exterior surface of the contact tip.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. non-provisional applicationSer. No. 14/541,069 filed on Nov. 13, 2014, entitled “NOZZLE INSERT FORAN ARC WELDING APPARATUS,” which claims the benefit of U.S. provisionalapplication Ser. Nos. 61/903,950 filed on Nov. 13, 2013 and 62/053,784filed on Sep. 22, 2014. The disclosures of the above applications areincorporated herein by reference in their entirety.

FIELD

The present disclosure relates generally to welding apparatuses, andmore particularly to arc welding apparatuses such as Metal Inert Gas(MIG) or Gas Metal Arc Welding (GMAW) welding guns, includingconsumables for generating a welding arc and diffusing a shield gas.

BACKGROUND

The statements in this section merely provide background informationrelated to the present disclosure and may not constitute prior art.

In an arc welding apparatus, such as Metal Inert Gas (MIG) or Gas MetalArc Welding (GMAW) welding gun, a welding wire is fed through thewelding gun to provide a molten metal pool to join metal workpiecestogether. An inert gas is directed through the front (distal) end of thewelding gun to provide a surrounding layer or blanket of shield gas toprotect the molten metal pool from atmospheric contamination. The inertgas is typically a combination of various gases such as argon or helium,among others.

A prior art MIG or GMAW welding gun typically includes a contact tip anda gas diffuser connected to the contact tip. The contact tip has acentral bore to guide the welding wire to the workpieces. The contacttip transfers electrical current to the welding wire. The gas diffuseris typically threaded to the contact tip and defines gas passagewaysthat direct the shield gas into a blanket of shield gas around themolten metal pool. The contact tip and gas diffuser are constantlysubjected to high heat and are susceptible to wear due to hightemperature operation.

SUMMARY

The present disclosure generally provides a contact tip/diffuserconfiguration for an arc welding apparatus, such as an MIG or GMAWwelding gun with an increased consumable life. The various forms of thepresent disclosure provide a simplified structure, more uniform heatdistribution and improved cooling to increase consumable life, amongother benefits.

In one form, a nozzle insert is used in a welding torch to secure acontact tip to a conductor tube. The nozzle insert comprises a bodydefining a longitudinal axis having a proximal end portion, a distal endportion. The body has a central bore that extends from the proximal endportion towards the distal end portion. The nozzle insert includes aninternal gas diverter disposed near the distal end portion of the body.The internal gas diverter defines a seating surface toward the proximalend portion and a profiled diverter orifice extends distally from thecentral bore.

In another form, an arc welding apparatus comprises a handle. Aconductor tube is attached to the handle and a welding cable isconnected to the handle. The welding cable carries welding current,shield gas and welding wire from a power source to the handle. Aconsumable assembly is attached to the conductor tube. The consumableassembly comprises a nozzle assembly. The nozzle assembly includes anozzle body, an insulator disposed within the nozzle body, and a nozzleinsert disposed within the insulator. The nozzle insert comprises aninternal gas diverter and a seating surface. A contact tip is disposedwithin the nozzle assembly. The contact tip defines a shoulder thatengages the seating surface of the nozzle insert. The contact tipcomprising at least one aperture extending from an exterior portion intoan internal cavity of the contact tip. The internal gas diverter directsa flow of shield gas exiting the aperture of the contact tip.

Further areas of applicability will become apparent from the descriptionprovided herein. It should be understood that the description andspecific examples are intended for purposes of illustration only and arenot intended to limit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustration purposes only and arenot intended to limit the scope of the present disclosure in any way.

FIG. 1 is a perspective view of an arc welding apparatus constructed inaccordance with the teachings of the present disclosure;

FIG. 2A is a front perspective view of a contact tip constructed inaccordance with the teachings of the present disclosure;

FIG. 2B is a rear perspective view of a contact tip constructed inaccordance with the teachings of the present disclosure;

FIG. 3 is a side view of various forms of the contact tip constructed inaccordance with the teachings of the present disclosure;

FIG. 4A is a side cross-sectional view of the contact tip constructed inaccordance with the teachings of the present disclosure;

FIG. 4B is an end cross-sectional view of the contact tip, taken alongline A-A of FIG. 4A, and constructed in accordance with the teachings ofthe present disclosure

FIG. 5 is a partial perspective view of the contact tip disposed withina nozzle assembly constructed in accordance with the teachings of thepresent disclosure;

FIG. 6 is a side cross-sectional view of a nozzle insert constructed inaccordance with the teachings of the present disclosure;

FIG. 7 is a side cross-sectional view of the contact tip and nozzleassembly of FIG. 5; and

FIG. 8 is a partial perspective view of a nozzle assembly with anotherform of the nozzle insert constructed in accordance with the teachingsof the present disclosure.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is in no wayintended to limit the present disclosure or its application or uses. Itshould be understood that throughout the description and drawings,corresponding reference numerals indicate like or corresponding partsand features. And although the term “MIG” or “GMAW” is used throughoutthe specification, it should be understood that the teachings of thepresent disclosure apply to any type of welding or cutting apparatus.

Referring to FIG. 1, an arc welding apparatus, such as a MIG or GMAWwelding gun, is illustrated and generally indicated by reference numeral10. The MIG welding gun 10 includes a handle 12, a conductor tube 14attached to the handle 12, and a consumable assembly 16 attached to theconductor tube 14. The handle 12 is connected to a welding cable 18 thatcarries welding current, shield gas, and a welding wire 20 from a powersource (not shown), a gas source (not shown), and a wire feeder (notshown) to the welding gun 10.

The consumable assembly 16 includes a plurality of consumable componentsincluding a nozzle assembly 22 and a contact tip 24 inside the nozzleassembly (contact tip 24 is shown in latter FIGS. 4 and 5). Thestructure and operation of an exemplary arc welding apparatus has beendisclosed in U.S. Pat. Nos. 5,491,321 and 5,338,917, which are commonlyowned by the assignee of the present application, and the contents ofwhich are incorporated herein by reference in their entirety.

The consumable assembly 16 is connected to a distal end portion 26 ofthe conductor tube 14. The nozzle assembly 22 is substantiallycylindrical in one form and receives the distal end portion 26 of theconductor tube 14 therein. The contact tip 24 is coaxially disposedinside the nozzle insert 22 and may be secured therein as illustratedand described in copending U.S. application Ser. No. 13/674,829 titled“Hollow Contact Tip-Diffuser for GMAW Manual/Robotic Arc Welding MIGGuns,” which is commonly owned with the present application and herebyincorporated by reference in its entirety. Further construction andoperation of an exemplary arc welding apparatus for which the teachingsof present disclosure may be applied are also described in greaterdetail in the aforementioned copending application.

Referring to FIGS. 2-4, various forms of the contact tip 24 according tothe present disclosure are now illustrated and described in greaterdetail. The contact tip 24 has a body 30 that defines an internal cavity32 extending from a proximal end portion 34 to a distal end portion 36.The contact tip 24 has a distal end face 38 and an exit orifice 39 thatextends through the distal end portion 36 of the body 30 and the distalend face 38. Advantageously, the contact tip 24 is designed to functionas both a contact tip for transferring electric current to the weldingwire and a gas diffuser for diffusing shield gas around the molten metalpool, thus providing a dual function while eliminating an additionalcomponent (i.e., a separate gas diffuser) from the consumable assembly16.

As shown in FIG. 3, the length and configuration of the contact tips 24can vary depending on application parameters such as amperage, wirediameter, duration of a welding operation, operating temperature, amongother parameters associated with the environmental and specific weldingapplication and welding process such as, by way of example, short arc,globular, spray transfer, and pulse. In addition, the length andconfiguration of the contact tips 24 may provide for customizing andimproving the flow of shield gas and cooling of the contact tip 24 alongwith the surrounding nozzle assembly 22 for a specific weldingoperation. As shown, a shorter contact tip 24 is used for example in alight duty application, the contact tip in the center 24′ for a mediumduty application, and the contact tip at the bottom 24″, for a heavyduty application. Typically, the duty cycle is determined by theduration of the weld operation and the amperage used during continuousoperation of the welding gun. For example, a light duty application maybe considered to be those welding operations that are rated and useapproximately 250 amperes and below. A medium duty application may beconsidered to be welding operations with a range from approximately 250amperes to approximately 350 amperes, and a heavy duty application isgenerally 350 amperes and above.

Referring now to FIG. 4A, the contact tip 24 according to one form ofthe present disclosure is further defined as having three sections, 40,50, and 60. The first section 40 includes an outer surface having aspherical tapered end portion 42 for engaging a corresponding sphericaltapered seat of a conductor tube (set forth above). Although a sphericaltaper geometry is shown, various other geometries may be used such astapered or polygonal configuration for the contact connection betweenthe contact tip 24 and a corresponding component such as a conductortube. The spherical tapered end 42 tapers outward from the proximal end34 toward the distal end portion 36. The first section 40 also defines ashoulder 44 facing distally, as shown.

The second section 50 is generally cylindrical and in one form definesat least one aperture 52 that extends through the body 30 into theinternal cavity 32. Although the aperture 52 is shown in arectangular/slotted configuration, it should be understood that anygeometrical shape, such as by way of example, round, oval, polygonal maybe employed while remaining within the scope of the present disclosure.Additionally, the apertures 52 may be normal to an outer surface 25 ofthe contact tip 24 or the apertures 52 may be angled in order tointroduce a swirling action to the shield gas while remaining within thescope of the present disclosure. Additional details and function of theapertures 52 are set forth in copending U.S. application Ser. No.13/674,829 titled “Hollow Contact Tip-Diffuser for GMAW Manual/RoboticArc Welding MIG Guns,” which has been incorporated by reference hereinabove.

A third section 60 in one form is tapered, and more specifically,tapering at an angle inward towards the distal end face 38 as shown. Thethird section 60 in this form tapers distally at a taper angle 62 fromthe second section 50 to the distal end face 38. The third section 60may further include variations to the taper angle 62 to accommodateapplication variables such as the diameter of the exit orifice 39 of thecontact tip 24 or a diameter of welding wire. Stated another way thethird section 60 is frustroconical and the outer diameter decreasestoward the exit orifice 39. By way of example, in one form of thepresent disclosure, the taper angle 62 varies between approximately 0-10degrees. It should be understood that the length and/or configuration ofeach section 40, 50, 60 of the contact tip 24 may vary according to thespecific welding application, such as by way of example, an extendedtapered section 60 for reach small/tight welding locations, or aconstant diameter contact tip throughout the second and third sections,50, 60.

As previously set forth, the contact tip 24 includes at least oneaperture 52 that extends through the body 30 of the contact tip 24 intothe internal cavity 32. The contact tip 24 is designed to direct theshield gas into the internal cavity 32 at the proximal end portion 34,and then out through the apertures 52 toward the distal end portion 36,along an exterior surface 25 of the contact tip 24. The flowcharacteristics of the shield gas will vary with the shape and positionof the apertures 52.

Referring more specifically to FIGS. 4A and 4B, in one form the contacttip 24 has four apertures 52 that are equally spaced as shown. Theapertures 52 in this form are each generally rectangular shaped slotsthat are further defined by an arcuate cut-outs 70 into the body 30 ofthe contact tip 24. The arcuate cut-outs 70 form guiding surfaces 72defined by a radius R1 on both sides of the aperture 52 that lead intothe internal cavity 32. The arcuate shape of the guiding surfaces 72direct the shield gas for a desired flow characteristic out of theaperture 52 of the contact tip 24. The apertures 52 may be any shape andthe guiding surfaces 72 may further be adjusted and varied to change theflow characteristics of the shield gas for various applications. Thenumber of apertures 52 and their spacing may be further modified toachieve a desired diffused flow of the shield gas. In one form, thetotal cross-sectional area of the apertures 52 is approximately equal tothe total cross-sectional area of the gas input to the welding cable 18at a power pin or plug holes (not shown). In this form, the apertures 52are designed so that the total cross-sectional area does not restrictthe flow of the shield gas beyond the restriction of the power pin orplug off of the gas supply (not shown). Additionally, the arcuatecut-outs 70 may be of various size radiuses R1. The size of the arcuatecut-outs 70 however, are generally sized to balance the desiredconduction heat transfer properties between the sections of the contacttip 24 and the desired gas flow characteristics created by the guidingsurfaces 72 as the shield gas exits the apertures 52. In the formillustrated, the radii R1 are approximately 5/32 inches. A diameter ofthe aperture 52 is largest at the inner side leading to internal cavity32 and is smaller at the outer surface leading to the external surface25.

Referring back to FIG. 4A, the flow of the shield gas through theapertures 52 can also be modified by varying the location of theapertures 52 along the body 30 of the contact tip 24. In one form theapertures 52 are located at a principal distance 80 measured from adistal edge 82 of the apertures 52 to the distal end face 38. Theprincipal distance 80 can advantageously be varied to adjust the flowand cooling effect of the shield gas around the contact tip 24, alongwith flow characteristics of the shield gas exiting the nozzle assembly22. The principal distance 80 between the apertures 52 to the distal endface 38 is at least a minimum distance to achieve the desired flow ofthe shield gas and the effectiveness of the shield gas to blanket themolten welding pool during the welding operation. The location of theapertures 52 in relation to the distal end face 38 allows for modifyingthe desired flow characteristics for each contact tip 24, to adjustoperational variables such as by way of example, a flow volume or flowpattern of the shield gas from the internal cavity 32. In one form, theprincipal distance 80 is at the minimum distance of approximately 0.8inches for the shield gas to achieve laminar flow properties along theexterior surface 25 of the contact tip 24. It should be understood thatthe principal distance 80 varies and could be greater or less than thisvalue for different operating conditions, such as size of the contacttip, flow volume and other parameters specific to the weldingapplication.

The taper angle 62 may further be modified to achieve a desired wallthickness 27 of the contact tip 24, proximate the distal end portion 36.The contact tip 24 and the desired wall thickness 27 may vary based onthe diameter of the exit orifice 39 or the gauge of the welding wire.The wall thickness 27 is germane for heat transfer through the contacttip 24 and in some instances may dictate the taper angle 62, forexample, with a larger diameter exit orifice 39. An insufficient wallthickness 27 may lead to increased/excessive local temperatures near thedistal end portion 36 and premature degradation/decreased life of thecontact tip 24, and more specifically a fusing or binding of the weldingwire within the contact tip 24. Therefore, to prevent prematuredegradation, the wall thickness 27 of the contact tip 24 defines aminimum thickness that is dependent on the duty cycle and ampere ratingof the welding operation. For example, in one form, the contact tip 24for the heavy duty application dictates the wall thickness 25 to beapproximately 0.12 inches. In another form, the contact tip 24 for amedium duty application dictates the wall thickness 27 of approximately0.08 inches. Additional modifications may include adjusting the lengthof the second section 59 and the third section 60 to maintain thedesired wall thickness 27 for a given gauge of welding wire. Forexample, in an instance of using a large gauge welding wire, the exitorifice 39 must be larger and the standard taper angle 62 may result ina wall thickness 27 that is too thin. Therefore, the taper angle 62 canfurther be changed to maintain the desired wall thickness 27 of thecontact tip 24.

Referring to FIG. 5, the nozzle assembly 22 includes a nozzle body 90that is in one form generally cylindrical, an insulator 92, and a nozzleinsert 94. As shown, the nozzle body 90 extends from a proximal opening96 to a distal opening 98. The nozzle body 90 may further include a noseportion 100 that may or may not narrow/extend inwardly to properlydirect the shield gas for a given application. The nozzle insert 94 hasa proximal end portion 104 and a distal end portion 102 and includes acentral bore 106 extending from the proximal end portion 104 towards thedistal end portion 102.

As shown in FIG. 6, the nozzle insert 94 includes a body 95 defining alongitudinal axis A and a central bore 106 extending from the proximalend portion 104 towards the distal end portion 102, and at its distalend portion 102 defines an internal gas diverter 110. The internal gasdiverter 110 further defines a seating surface 112 toward the proximalend portion 104 of the nozzle insert 94. The seating surface 112 ischamfered in one form, for engaging the shoulder 44 of the contact tip24. (Referring to FIG. 7, the shoulder 44 of the contact tip 24 is shownspaced apart from the seating surface 112 in order to illustrate thesefeatures in detail). As further shown, the internal gas diverter 110defines a profiled diverter orifice 120 that extends distally from thecentral bore 106. The profiled diverter orifice, as shown in FIGS. 6 and7, includes a single surface that defines a chamfer that extends at anangle relative to the longitudinal axis of the body.

Referring to FIG. 7, the nozzle body 90 may further include an interiordiverter surface 130 for further directing the shield gas exiting theapertures 52 of the contact tip 24. In this form, the shield gas flow isdirected by the interior diverter surface 130 within a convergentsection 132 into a throat 134, and then the shield gas enters adivergent section 136 of the nozzle body 148. In this form, thedivergent section 136 has an increasing diameter from the throat 134 toa distal opening 98 of the nozzle body 90. The nozzle body 90 includingboth the convergent section 132 and the divergent section 136 results inflow characteristics that are more laminar when exiting the distalopening 98. In addition, the divergent section 136 directs the shieldgas out the distal opening 98 to fan outward, widening the coverage ofthe shield gas over the weld pool during the operation of the weldinggun 10. The convergent and divergent sections 132, 136 are designed tofurther improve and customize the flow characteristics of the shield gasfor the specific welding operation. The lengths, diameters and interiorgeometry of the nozzle body 90 may include various permutations to allowfor the shield gas to be optimized for a specific welding operation andenvironment. For example, the divergent section 136 may extend at agreater angle from the throat 134, further directing the shield gas intoa larger fan outward of the distal opening 98. Alternately, thedivergent section 136 may extend at or near the same diameter as thethroat 134, thus directing the shield gas in a narrower fan exiting thedistal opening 98.

As shown in FIGS. 5 and 7, the profiled diverter orifice 120 of thenozzle insert 94 extends around the apertures 52 of the contact tip 24.The gas flow, indicated by the dashed arrows F, is directed distallythrough the internal cavity 32 of the contact tip 24, and then radiallyoutwards through the apertures 52. The profiled diverter orifice 120then directs the gas flow exiting the apertures 52 distally around theexterior surface 25 of the contact tip 24 as shown. The profileddiverter orifice redirects the shield gas flow as is further discussedbelow. It is appreciated that various angles may be utilized and thesingular angles surface is just one possible form.

Referring to FIG. 8, in another form, the profiled diverter orifice 120may extend various lengths L along the longitudinal axis A. The profileddiverter orifice 120 may define a surface from a contact seat 160 andinclude a variety of geometrical configuration. For example, theprofiled diverter orifice 120 as illustrated extends at two differentangles relative to the longitudinal axis A. Stated in another way theprofiled diverter orifice 120, in one form, defines a surface thatextends at a first angle from the contact seat 160 and the surfaceextends a length L along the longitudinal axis. The profiled diverterorifice 120 further defines the surface extending a length L at a secondangle relative to the longitudinal axis. The profiled diverter orifice120 may include multiple angles to tune the gas flow characteristics orcooling of the contact tip 24 and surrounding nozzle assembly 22. Theprofiled diverter orifice 120 may change geometrical shape andconfiguration to further tune the flow characteristics of the shield gasfor a specific welding application.

The nozzle insert 94 may be manufactured by various methods includingmachining or a metal injection molding process, also known as MIM. Inaddition, the nozzle insert may be made from various metals and alloys,for example, in one form the nozzle insert 94 is made of brass.

The present disclosure is merely exemplary in nature, and thus,variations that do not depart from the spirit of the disclosure areintended to be within the scope of the present disclosure. Suchvariations are not to be regarded as a departure from the scopecontemplated in the present disclosure.

What is claimed is:
 1. An arc welding apparatus comprising: a handle; aconductor tube attached to the handle; a welding cable that carrieswelding current, shield gas, and a welding wire, the welding cable beingconnected to the handle; and a consumable assembly attached to theconductor tube, the consumable assembly comprising: a nozzle assemblycomprising a nozzle body, an insulator disposed within the nozzle body,and a nozzle insert disposed within the insulator, the nozzle insertcomprising an internal gas diverter and a seating surface; and a contacttip disposed within the nozzle assembly, the contact tip defining ashoulder that engages the seating surface of the nozzle insert and thecontact tip further comprising at least one aperture extending from anexterior surface into an internal cavity; and wherein the internal gasdiverter directs a flow of shield gas exiting the at least one aperturealong the exterior surface of the contact tip.
 2. The arc weldingapparatus according to claim 1, wherein the internal gas diverterincludes a profiled diverter orifice that surrounds the contact tip andthe profiled diverter orifice includes a geometry for directing shieldgas exiting the at least one aperture of the contact tip.
 3. The arcwelding apparatus according to claim 2, wherein the profiled diverterorifice extends around the at least one aperture of the contact tip. 4.The arc welding apparatus according to claim 2, wherein the profileddiverter orifice directs the shield gas exiting the at least oneaperture of the contact tip around the exterior surface of the contacttip.
 5. The arc welding apparatus according to claim 2, wherein thenozzle insert further comprises a body defining a longitudinal axishaving a proximal end portion, a distal end portion, and a central boreextending from the proximal end portion towards the distal end portion.6. The arc welding apparatus according to claim 5, wherein the profileddiverter orifice further defines a chamfer at an angle relative to thelongitudinal axis of the body.
 7. The arc welding apparatus according toclaim 5, wherein the profiled diverter orifice extends at an angle to,and a length along, the longitudinal axis.
 8. The arc welding apparatusaccording to claim 1, wherein the nozzle insert further defines aplurality of threads for securing the nozzle assembly to the conductortube.
 9. The arc welding apparatus according to claim 8, wherein thenozzle assembly threadably attaches to the conductor tube by the nozzleinsert, and the nozzle insert engages against the shoulder of thecontact tip with the seating surface and secures the contact tip to theconductor tube.
 10. The arc welding apparatus according to claim 9,wherein the conductor tube further comprising a spherical tapered seatand the nozzle insert secures the contact tip into the spherical taperedseat.
 11. The arc welding apparatus according to claim 1, wherein thenozzle insert comprises one selected from a metal, a metal alloy, or abrass alloy that is capable of withstanding an amperage applied to theconsumable assembly and the heat generated during the use of the arcwelding apparatus.
 12. The arc welding apparatus according to claim 11,wherein the nozzle insert is manufactured by one of a machiningoperation or a metal injection molding.
 13. The arc welding apparatusaccording to claim 1, wherein the nozzle body further includes aproximal opening, a distal opening opposite the proximal opening, aconvergent section, a divergent section, and a throat section, thedivergent section being disposed more proximate to the distal openingthan the convergent section and the throat section, and the convergentsection being disposed more proximate to the proximal opening than thedivergent section and the throat section.
 14. The arc welding apparatusaccording to claim 13, wherein the nozzle body further includes aninterior diverter surface disposed in the convergent section thatdirects shield gas into the throat section.
 15. The arc weldingapparatus according to claim 13, wherein the convergent section has afirst diameter and the throat section has a second diameter, the firstdiameter being greater than the second diameter.
 16. The arc weldingapparatus according to claim 15, wherein the divergent section includesa third diameter that increases in size from the throat section to thedistal opening of the nozzle body.
 17. An arc welding apparatuscomprising: a handle; a conductor tube attached to the handle; a weldingcable that carries welding current, shield gas, and a welding wire, thewelding cable being connected to the handle; and a nozzle assemblyattached to the conductor tube and configured to secure a contact tip tothe conductor tube, the nozzle assembly comprising: a nozzle body havinga distal opening and an opposite proximal opening, an insulator disposedwithin the nozzle body, and a nozzle insert disposed within theinsulator, the nozzle insert defining a longitudinal axis and having aproximal end portion, a distal end portion, and a central bore extendingfrom the proximal end portion towards the distal end portion, the insertfurther comprising: an internal gas diverter disposed proximate to thedistal end portion of the nozzle insert, the internal gas diverterdefining a seating surface facing toward the proximal end portion and aprofiled diverter orifice, wherein the profiled diverter orifice isdefined by a surface facing toward the distal end portion of the body,the surface extending radially outward from the longitudinal axis alonga length of the surface toward the distal end portion, the length of thesurface extending distally from the central bore to the distal endportion.
 18. The arc welding apparatus according to claim 17, whereinthe profiled diverter orifice surrounds the contact tip and the profileddiverter orifice includes a geometry for directing shield gas exiting atleast one aperture of the contact tip around an exterior surface of thecontact tip.
 19. An arc welding apparatus comprising: a handle; aconductor tube attached to the handle; a welding cable that carrieswelding current, shield gas, and a welding wire, the welding cable beingconnected to the handle; and a consumable assembly attached to theconductor tube, the consumable assembly comprising: a nozzle assemblycomprising a nozzle body, an insulator disposed within the nozzle body,and a nozzle insert disposed within the insulator, the nozzle insertcomprising a distal end portion, a proximal end portion, and an internalgas diverter disposed proximate to the distal end portion, the internalgas diverter comprising: a profiled diverter orifice having a surfacefacing toward the distal end portion and extending radially outward froma longitudinal axis of the nozzle insert along a length of the surfacetoward the distal end portion, and a seating surface facing toward theproximal end portion; and a contact tip disposed within the nozzleassembly, the contact tip defining a shoulder that engages the seatingsurface of the nozzle insert, the contact tip further comprising atleast one aperture extending from an exterior surface into an internalcavity; and wherein the profiled diverter orifice directs a flow ofshield gas exiting the at least one aperture along the exterior surfaceof the contact tip.
 20. The arc welding apparatus according to claim 19,wherein the nozzle insert further defines a plurality of threads forsecuring the nozzle assembly to the conductor tube, the nozzle insertengages against the shoulder of the contact tip with the seating surfaceto secure the contact tip to the conductor tube.